The present invention relates to a solar ray device for illumination and more particularly to an effective combination of a solar ray collecting device and a illuminator for radiating the solar rays collected by said solar ray collecting device. The solar ray collecting device has a control means for realizing the rotation of a number of optical lenses so as to always direct them toward the sun, a plurality of light-guiding cables (or fiber optic cables) into which the solar rays collected by said lenses are guided. The illuminator radiates the solar rays transmitted by said light-guiding cables (or fiber optic cables).
The present applicant previously proposed a solar ray collecting device accommodated in a capsule. The capsule is composed of a cylindrical base body, a transparent dome-shaped head and a transparent connecting portion for connecting said base body with said head. The solar ray collecting device comprises a large number of lenses (for example, 7, 19 . . . etc.) a solar ray direction sensor for detecting the sun's location, a supporting frame for integrally holding the lenses and sensor, a first revolving shaft for rotating the support frame, a first motor for rotating the first revolving shaft, a support arm for supporting the lenses and the motor, a second revolving shaft installed so as to intersect the first revolving shaft perpendicularly thereto, and a second motor for rotating the second revolving shaft. The direction of the sun is detected by means of the solar ray direction sensor and its detection signal controls the first motor and the second motor so as to always direct the lenses toward the sun, and the sunlight, focused by the lenses, is guided into a light-guiding cable (or fiber optic cable) through its end-surfaces set at the focal points of the lenses. The guided sunlight is transmitted through the light-guiding cable (or fiber optic cable) to wherever the light is needed for illumination or for other purposes. It shall be understood that a fiber optic cable is made up of a bundle of single cables each of which is made up of a large number of optical fibers, and a light-guiding cable is a bundle of a number of fiber optic cables.
The above-mentioned solar ray collecting device is intended to focus solar rays through lenses and transmit them through a light-guiding cable (or fiber optic cable) to wherever the light is needed. Said light-guiding cable {or fiber optic cable) is a bundle of cables whose light-emitting ends are to be unbound and separated from each other for directly radiating the light rays or for radiating the same through optical means such as lenses or the like. However, by this method it is difficult to uniformly illuminate a whole area. When an area to be illuminated is enlarged, the light radiation becomes unnaturally decreased in intensity at the peripheral portion. Furthermore, in the case where a solar ray collecting device and an illuminator are constructed as separate units with separate cabling, the mutual connecting of their light-guiding cables' ends has to be conducted by using a special connecting means which may result in an increased loss of light transmission.